Patient portrayal

Knowing is strength.

Learn more about the science of genetic ALS.

For many, ALS appears without warning and seemingly without reason. But for more than 10% of ALS patients, ALS may be caused by specific genes in the body’s cells that may no longer work correctly. This is called genetic ALS.

Welcome to insideALS

At insideALS.com, you will find resources about genetic ALS that have been developed by Biogen in consultation with ALS specialists and patient advocacy groups for people living with ALS and caregivers.

Important facts about genetic ALS.

Patient portrayal

Not all ALS is the same.

ALS is a rare, progressive, and fatal disease that usually affects people between the ages of 40-70. It is usually divided into two groups: familial ALS (fALS), which is inherited from a family member and sporadic ALS (sALS), where the person diagnosed does not have a known family history of the disease.

Approximately 5-10% of ALS patients have fALS, while sALS accounts for about 90-95% of all ALS cases. Recent scientific discoveries have identified more than 25 genes that have been linked to ALS. A number of these genes have been found in both fALS and sALS patients. This means that even if a person is the only known family member diagnosed with ALS, a genetic component may be involved. Cases that have a genetic component – across both fALS and sALS – are referred to as “genetic ALS.”

A closer look at the most common genes associated with ALS.

To date, over 25 genes have been discovered that are associated with ALS. The most common genes are SOD1 and C9orf72, which are described in more detail below. By learning more about the genes associated with ALS, the ALS community hopes to learn more about the disease and how it may progress.

SOD1-ALS

The first gene that was discovered to be associated with ALS was SOD1. In people with SOD1-ALS, the SOD1 gene has undergone a change, or mutation, which results in damage to nerves in the brain and spinal cord that control muscle movement.


SOD1 gene mutation accounts for just 2% of all ALS cases. Among all ALS patients with a genetic component, approximately 20% are associated with a mutation of the SOD1 gene.
For half of the patients with SOD1 ALS there is no known family history of ALS.

2 in 10

GENETIC ALS CASES ARE
DUE TO SOD-1 MUTATION

1 in 2

SOD1-ALS PATIENTS DO
NOT HAVE A KNOWN
FAMILY HISTORY OF ALS

C9orf72-ALS

C9orf72 is short for “chromosome 9 open reading frame 72,” and is the most common ALS-linked gene mutation, affecting approximately 33% of familial ALS patients and 5% of sporadic ALS patients. As there are many more sporadic ALS patients than familial ALS patients, it is thought that there may be more C9orf72 ALS patients who do not have a known family history of ALS.

Patient portrayal

Knowing is clarity.

If you are a person living with ALS or a caregiver, it could be important to know if a genetic form of ALS may be affecting you or your loved one.

Genetic testing for all people living with ALS—those with a known family history of ALS and those that do not have a known family history of ALS—may help in understanding the condition better and could assist with long-term life choices. Clinical trials targeting genetic forms of ALS offer a reason to find out which ALS-associated genes you may carry.

Genetic testing across patients with seemingly sporadic ALS.

Total estimated ALS population: 222,801
Est. population: 200,520
sALS
~90-95% of total
Est. population: 22,280
fALS
~5-10% of total
~10% of sALS patients have a known genetic component
Est. population: 20,052
~70% of fALS patients have a known genetic component
Est. population: 15,596
sALS
~90-95% of total
Est. population: 200,520
~10% of sALS patients have a known genetic component
Est. population: 20,052
fALS
~5-10% of total
Est. population: 22,280
~70% of fALS patients have a known genetic component
Est. population: 15,596
Patient estimates based on 222,801 patients worldwide (2015). Worldwide ALS patient population estimates based on representative country incidence rates applied to their continent's population, as well as a pooled analysis of Europe.

It is important to stay up to date with genetic ALS information.

The science of genetic ALS is changing, and ALS specialists and researchers are learning more about ALS-associated genes. There are a growing number of clinical trials focused on genetic ALS that are enrolling new patients as well. By staying up to date with information about genetic ALS, you and your loved ones can be better equipped to talk with your physician about your condition.